The invention relates to a large-sized transportable projection screen, having a fillable, shape-variable hollow body in the form of a structure made of fillable tubes.
A large-sized projection screen is known from US 2004/0211100 A1. WO 02/47057 A1 describes another apparatus with a three-dimensional construction for displaying visible images, with an inflatable body and a base. The body is formed by tube-like parts which, in the inflated state, have a predetermined shape in order to provide at least one display surface for displaying the visible images. U.S. Pat. No. 6,008,938 describes another transportable projection screen which can be inflated with cold air and is clamped between two inflatable towers and an inflatable tube connecting the towers. The two-dimensional structure is held upright by holding lines and extension arms fastened to the towers and is fastened to the ground.
A further two-dimensional projection screen has, according to DE 3028258 A1, a flexible, concave projection surface and an inflatable frame, and therefore said frame can be placed under pressure for stiffening purposes and in order to keep the projection surface stretched, with the frame being designed in such a manner that it forms a stray-light shade. Planar, two-dimensional large-sized projection screens which have inflatable supports are also known.
A planar structure of a large-sized transportable projection screen is known from DE 100 34 912 A1 and DE 203 18 473 U1. In DE 100 34 912 A1, a frame is formed by bringing together the ends of elongated tubes which can be filled with gaseous media and are made of flexible materials. According to DE 203 18 473, a virtually flat, inflatable hollow surface is formed, said hollow surface being formed from a plurality of individual, fixedly interconnected, sequentially fillable hollow bodies which are arranged parallel to one another. This planar structure also requires ropes, straps or rods for anchoring the structure in a stabilizing manner on the ground.
A screen which can be inflated with cold air, is inflated in a manner similar to a balloon and which is also bounded by walls formed by pockets which can likewise be inflated is known from U.S. Pat. No. 4,802,734. In order to keep the balloon-like structure in shape, the top and bottom surfaces within the balloon are pulled counter to each other by ropes. Only a curved realization of a projection surface is possible with the balloon-like structure. It also has an extremely high loss of air for the operation and, due to the pressurized interior filling, can only be walked on to a limited extent.
It would be desirable to improve both the stability and the picture quality of a large-sized projection screen.
This is the starting point of the invention, the object of which is to provide a large-sized transportable projection screen, the stability and picture quality of which are substantially improved.